Terror dogs are found at the end of Tarn's Lair. They can be killed at level 40 Slayer.

During The Lair of Tarn Razorlor, four of these need to be fought alongside some animated armour and Tarn Razorlor. They rarely use their magic attack, only using it when out of melee range, and it is very weak and inaccurate. After Tarn Razorlor has been slain, their mass melee rush in a multi-combat, prayer-draining area, can create problems for the unprepared.

Terror dogs do not count toward fulfilling a Slayer task for dogs; they are a separate task.

Players can hide in Tarn's room just north of the Terror dogs and wait for them to develop tolerance to the player. This makes combating them significantly less risky. Be sure to log out to check for tolerance, as any dogs aggressive towards the player will remain so until the player exits Tarn's room, even if all other dogs are no longer aggressive. This will also cause all dogs targeting the player to stop and begin wandering around. Players can check to see if the dogs are still aggressive by exiting Tarn's room and waiting at the door for a quick retreat if they are.

Terror dogs are similar to hellhounds in that they can hit hard and accurately, but have very low Defence. Unlike hellhounds, terror dogs attack in swarms.

Fighting terror dogs (mostly done for Slayer tasks) can be a difficult and annoying task for the unprepared. With the proper equipment, this task becomes a cake-walk. High-level players with healing equipment can fight them indefinitely. They can be safespotted if standing in the recesses after they have became tolerant of players. They can also be safespotted by luring one to the entrance of the tunnel to Tarn's room, and ranging it directly from the other side of the tunnel.

Teleporting with the slayer ring is ideal, otherwise the player will have to reach the terror dogs by traveling through Tarn's Lair. You might want to wear dragonhide armour or bring prayer potions if you are under 37 Prayer, as the skeleton mages' magic attacks can hit hard on metal armour without Protect from Magic up. If you opt for dragonhide, remember that terror dogs are melee creatures. Before entering the room, make sure to change into better melee armour.

Finally, as noted above, terror dogs will multi-attack players, subjecting them to constant and accurate melee attacks from several sides at once.
Finally, note that terror dogs can hit frequently and hard, so players should pay particular attention to their Hitpoints when fighting them. For example, even when using Guthan's set, a series of terror dog hits can sometimes cause damage much faster than the equipment can heal the player. An emergency teleport is recommended if players experience difficulty staying above half their Hitpoints.